Joint forming apparatus for concrete surfaces



JOINT FORMING APPARATUS FOR CONCRETE SURFACES Filed May 27, 1966 R. A. HANSON May 7, 1968 7 Sheets-Sheet 1 INVENTOR. IPA YMOND A. H ANGOIX y 7, 1968 R. A. HANSON 3,381,595

JOINT FORMING APPARATUS FOR CONCRETE SURFACES Filed May 27, 1966 '7 Sheets-Sheet 2 RAYMOND A. HANSON INVENTOR.

R. A. HANSON 3,381,595

JOINT FORMING APPARATUS FOR CONCRETE SURFACES May 7, 1968 7 Sheets-Sheet 3 Filed May 27, 1966 Q m wm mm 3 0 m mm m k R Q wm N o o I mm mm km, 0 ww mm m mm m a w m 5 mm. L 2 mm mm II i lllllllllllll lllll-llllll I. w

INVENTOR.

RAYMOND A. HANSON BY A'TT Y8.

y 7, 1968 R. A. HANSON 3,381,595

JOINT FORMING APPARATUS FOR CONCRETE SURFACES Filed May 27, 1966 7 Sheets-Sheet 4 3% m: 5/ 50 i 40 7/ 471 3g b1 4! I as f HINVENTOR. h RAYMOND A. HANSON y 1968 R. A. HANSON 3,381,595

JOINT FORMING APFARATUS FOR CONCRETE SURFACES Filed May 27, 1966 7 Sheets-Sheet 5 INVENTOR. RAYMOND A HANSON y 7, 1963 R. A. HANSON 3,381,595

JOINT FORMING APPARATUS FOR CONCRETE SURFACES Filed May 27, 1966 7 Sheets-Sheet 6 35 as 25 l0 1 NVEN TOR. U I RAYMOND A. HANSON 1968 R- A. HANSON 3,381,595

JOINT FORMING APPARATUS FOR CONCRETE SURFACES 7 Filed May 27, 1966 7 Sheets-Sheet '2 INVENTOR. RAYMOND A. HANSON A TTYS.

United States Patent 3,381,595 JOINT FORMING APPARATUS FOR CONCRETE SURFACES Raymond A. Hanson, R. A. Hanson Co., Palouse, Wash. 99161 Filed May 27, 1966, Ser. No. 553,416 Claims. (Cl. 94-45) ABSTRACT OF THE DISCLOSURE A joint forming apparatus including a supporting framework carried by tracks along a concrete slab. One or more movable frames are vertically adjustable relative to the framework and carry joint forming devices for producing a slot in the slab surface. The joint forming devices include slotting blades and associated discs, and reciprocating movement is imparted to both the discs and blades by appropriate powered devices. Automatic control of the elevation of the slotting devices is also disclosed.

This invention relates to a jont forming apparatus for concrete surfaces such as concrete slabs poured along a highway or lined canal.

It is conventional to provide joints of one type or another extending longitudinally or transversely through concrete slabs of relatively great dimensions, such as are utilized in the surfacing of highways and in the lining of canals. The device shown in this disclosure is designed particularly for forming longitudinal and transverse joints as required along the length of a lined canal. However, it is to be understood that the apparatus could be equally applicable to the forming of similar joints on any concrete slab.

The apparatus shown in the drawings includes a rigid jumbo or supporting framework carried by ground engaging tracks at its transverse ends and adapted to be moved longitudinally along the concrete slab at an elevation located upwardly adjacent to the upper slab surface. This framework is shown with both a longitudinal joint forming device and with several transverse joint forming devices which act conjointly to cut a transverse joint while the framework is stationary. The joint forming devices are elevationally movable relative to the framework. The manner of mounting these devices and the controls associated therewith form an important part of this invention. Likewise, the invention is concerned with the details of the joint forming devices themselves and the manner in which a joint is formed in the concrete surface previously poured.

It is a first object of this invention to provide a joint forming apparatus independent of other concrete machinery, the apparatus being normally used immediately behind a slipform or other finishing device. The independent nature of this apparatus permits the utilization of the slipform with a continuous movement so that it need not be stopped to cut a transverse joint. It also permits the operator of the joint forming apparatus to delay the cutting of the joint until the optimum time relative to the curing of the concrete, it being understood that the curing rate of concrete will vary depending upon external conditions.

Another object of this invention is to provide an automatic control apparatus for locating the concrete joint forming devices relative to the slab surface through which they must protrude so that the formed joint is accurately defined at a constant depth.

Another object of this invention is to provide a transverse joint cutting apparatus which utilizes several identical devices acting in concert to lessen the time required to cut a transverse joint across a wide slab.

Another object of this invention is to provide an improved mechanism for cutting a slot through a previously finished concrete surface with minimum disturbance of the concrete previously placed to insure the formation of an accurate joint.

These and further objects will be evident from the following disclosure, taken also with the accompanying drawings which illustrate a preferred form of the invention designed for cutting such joints along a canal surface. It

is to be understood that the illustrated device is only one example including the concepts of this invention and that it is not to precisely limit the scope of the invention itself.

' In the drawings:

FIGURE 1 is a perspective view showing the instant apparatus in operation;

FIGURE 2 is a front elevation view of the apparatus shown in FIGURE 1, the supporting ground and concrete surfaces being shown in section;

FIGURE 3 is a top view of the apparatus shown in FIGURE 2;

FIGURE 4 is an enlarged fragmentary view through the apparatus taken along line 44 in FIGURE 2;

FIGURE 5 is atop view of the longitudinal joint cutting device as seen along line 55 in FIGURE 4;

FIGURE 6 is an elevational sectional view at an enlarged scale taken along line 6-6 in FIGURE 5;

FIGURE 7 is an enlarged fragmentary sectional view of the control apparatus as seen along line 77 in FIG- URE 5;

FIGURE 8 is an enlarged vertical sectional view taken adjacent to one of the transverse joint cutting devices as seen along line 88 in FIGURE 4;

FIGURE 9 is a view similar to FIGURE 8, showing the modified joint cutting device used at the lower portion of the apparatus;

FIGURE 10 is a top view of the apparatus in FIGURE 9 as seen along line 1010; and

FIGURE 11 is an enlarged vertical sectional view taken through the joint cutting apparatus as seen along line 1111 in FIGURE 8.

Referring now to the drawings, the general features of the machine are shown in FIGURES 1, 2 and 3. It includes a rigid supporting framework 10 that extends transversely across the slab of freshly poured concrete relative to the intended longitudinal movement of the apparatus along the slab. In the drawings there is shown a framework 10 designed for use in forming longitudinal and transverse joints along the length of a canal, the apparatus being designed to cut transverse joints along the sloping sides of a canal and along a portion of the horizontal lower canal surface. It also has a single unit for cutting a longitudinal joint spaced along the sloping side wall.

Framework 10 is supported with its lower portion upwardly adjacent to the upper slab surface by tracks 11 mounted at its transverse ends. The track units 11, of conventional construction, are movably mounted on framework 10 by cylinders 12 and parallelogram support arms or other mounting devices.

Framework 10 is shown with a transverse front lower beam 13 and corresponding rear beam 14. Along the upper portion of framework 10 is a transverse catwalk 15 to permit those working on the machine to have access to the elements carried on framework 10 during use of the apparatus on freshly poured concrete. The section of framework 10 that extends along the slope portion of the slab is denoted generally by the numeral 16 and that which extends along the horizontal bottom section of the canal is designated by the numeral 17.

The joint forming apparatus described herein actually includes five quite similar joint cutting devices, four of these being used to form the transverse joint during the time in which the framework 10 is stationary and the fifth being used to form a longitudinal joint when the framework is moved longitudinally along the length of the slab. These five units are quite similar and identical reference numerals are used in the drawings to identify the corresponding parts of each. They differ in the manner in which they are mounted on framework 10 and, in one instance, in the dimensional relationship between the supporting apparatus on framework 10 and the joint cutting apparatus.

The first joint cutting unit to be described is that used to form the longitudinal joint shown at 9 in FIGURE 1. This is shown in detail in FIGURES 4 through 7.

The joint forming device shown in FIGURES 4 through 7 is mounted on a forwardly protruding rectangular framework section 18 fixed to the lower front beam 13 of framework 10 and rigidly carried by a supporting triangular brace structure 20 anchored to framework 10 along the upper edge thereof. A movable frame 22, also generally rectangular in shape, is mounted within the framework extension 18. It is connected to the framework extension 18 by two pair of parallel links 31 at the respective sides of the extension 18. The links 31 are pivoted to the framework extension 18 and to frame 22 respectively about parallel transverse horizontal axes, so that the frame 22 is capable of elevational adjustment relative to framework extension 18. The parallelogram links 31 will at all times maintain the frame 22 parallel to the framework extension 18.

The elevational position of frame 22 relative to framework extension 18 is controlled by an upright cylinder 32 and reciprocating piston rod 33 controlled thereby. The lower end of cylinder 32 is pivotal-1y mounted on frame 22 by upright pivot brackets 36 and transverse horizontal mounting stud shafts 35. The lower end of piston rod 33 is pivotally connected to the cross member on framework extension 18 by means of a pivot bracket also connected about a transverse horizontal axis. The parallel pivotal connections at the lower end of cylinder 32 and the lower end of rod 33 prevent binding of the cylinder and rod during elevational adjustment of frame 22 relative to framework extension 18.

At both the front and rear of frame 22 are compression springs 37 to assist in supporting the weight of frame 22 and the associated mechanisms mounted thereon. Each compression spring 37 is located by a lower mount 38 on framework extension 18 and an arched upper mount 40 on frame 22. Because of the springs 37, the cylinder 32 does not need to lift the entire weight of frame 22. Frame 22 substantially floats on the framework extension 18, the elevational position of frame 22 being regulated by operation of cylinder 32, a conventional double-acting hydraulic or pneumatic cylinder.

The details of the joint cutting device can be seen in FIGURE 6. The joint cutting device also is shown in other views, particularly FIGURES 8 and 11, where it is shown in one of the transverse joint forming elements. The joint formed by the particular apparatus described is simply a slot formed through the upper surface of the freshly poured concrete slab. It is to be understood that various devices might be utilized to place joint material within this slot, either using a pro-formed joint of one or more longitudinal sections or by pouring joint material into the formed slot.

The joint cutting device 41, which protrudes beneath frame 22, comprises a lower upright blade 42 having an arcuate front lower edge surface that extends rearwardly to provide a cutting surface for penetrating the concrete surface. The blade 42 has a transverse plate 43 extending to each side of it to assist in preventing blade 42 from penetrating too deeply and to maintain a smooth upper surface on the concrete slab at each side of the slot formed by blade 42. A mounting plate 44 extends upwardly from the transverse plate 43 and serves as the connection between the joint cutting device 41 and the 4 frame 22. At its rear end, plate 44 is pivotally carried about a pivot connection 45 oriented along a transverse horizontal axis. The pivot connection 45 is provided at the lower end of a downwardly extending bracket 46 fixed as a part of frame 22.

The front end of plate 44 is oscillated slightly in a vertical plane about the axis of pivot connection 45. The motion imparted to the front end of blade 42 is transmitted through a transverse shaft 47 rotatably journalled on frame 22. Shaft 47 is powered by a motor 48 fixed to the frame 22 having a driven pulley 50. Pulley 50 drives a similar pulley 52 on a transmission unit connected to shaft 47, the connection between pulleys 50 and 52 being provided by a belt 51 (FIGURE 8).

An eccentric bearing 54 is mounted on shaft 47 in vertical alignment above the joint cutting device 41 (FIG- URE 11). The eccentric bearing 54 is connected to an adjustable link 55 pivotally connected to the forward end of the upright plate 44 previously described. Alternate apertures 57 are provided through the plate 44 for selective connection to the link 55, depending upon the degree of movement and the angle of approach desired in order to insure proper penetration of blade 42 in a particular instance.

Trailing rearward of the blade 42 is a rear cutting device 58 in longitudinal alignment with it. It is connected to plate 43 by a flexible connection 60 of rubber or other suitable flexible material. The rear cutting device 58 also includes a downwardly protruding blade 61 having a forward arcuate edge and a pair of transversely extending plates 62 which lie in the same plane as plates 43 and which are also in an engagement with the surface of the slab. A light compression spring 63 is connected between frame 22 and the rear of the device 58 to insure that the blade 61 and plate 62 are in proper engagement with the concrete slab.

The longitudinal joint cutter also includes a rotating disc 64 mounted forwardly of the joint cutting device 41. Disc 64, having a tapered peripheral circular edge, is carried on a transverse shaft 65. It is positioned by side plates 66 fixed to shaft and having axial bolts 67 ad justably carried thereby. The bolts 67 bear against the disc 64 and angular-1y position disc 64 at a slight angular deviation from a plane perpendicular to the axis of shaft 65. Rotation of shaft 65 will therefore cause the disc 64 to wobble slightly. The disc 64 has a thickness less than that of blade 42, the amount of wobbling motion im' parted to disc 64 enabling the disc 64 to open a slot sub stantially the same in width as that formed by the blade 42. The lower periphery of disc 64 should be elevationally positioned at substantially the same elevation as the lower edge of blade 42.

Shaft 65 is powered by a sprocket 68 on shaft 47 and a driven sprocket 70 on shaft 65. The two sprockets 68, 70 are encircled by a driving chain 71. Shafts 47 and 65 are rotated continuously during use of the device in forming a joint.

To provide automatic monitoring of the position of frame 22 relative to framework extension 18, the control apparatus generally shown in FIGURE 7 is utilized. Mounted within the control housing of the two on frame 22 is a spool valve 73 having discharge ports connected to the upper and lower ends of cylinder 32. The spool valve 73 should be quite sensitive so as to detect slight rotational movement of the spool used to control the flow of fluid to cylinder 32. The spool of valve 73 is connected to a radially extending control element 73a that extends rearwardly in contact with the upper slab surface. It is obvious from FIGURE 7 that elevational deviation of frame 22 relative to the slab surface will be detected by the spool valve 73 due to the resulting rotation of the spool caused by the control element 73a. If frame 22 is lowered relative to the slab, the valve 73 will be auto matically actuated to extend rod 33 outwardly from cylinder 32 and therefore raise frame 22. A similar correction will be effected if the frame 22 should rise above the desired elevation relative to the slab.

Also generally shown is a controlling solenoid 75 within housing 72 having an actuating arm 75a that is normally biased downwardly by a tension spring 76. The arm 75a is in loose engagement with a protruding rigid arm 74 also fixed to the spool of the valve 73. Solenoid 75 is actuated when automatic control of the elevation of frame 22 is no longer desired. Such operation will cause the arm 75a to lift arm 74 and therefore will cause valve 73 to raise frame 22 relative to the framework extension 18. This will be accomplished at any time in which the cutting of the joint is not desired or necessary. In the case of the units cutting the transverse joints, such lifting is required each time the joint cutting units must be returned to the upper end of framework prior to forming a new joint.

The units used to cut the transverse joint are shown in FIGURES 8 through 11, the device shown in FIGURES 9 and 10 being the shortened unit at the lower end of the machine. The three other units along the slope portion of framework 10 are constructed as shown in FIGURES 8 and 11. There is little difference between these two types of units, and the same numerals will also be applied to these as were applied to the longitudinal joint forming device illustrated in FIGURES 4 through 7.

The transverse joint forming devices are movably carried on a track 24 at the front and rear of framework 10 fixed to the framework 10 by transverse track supports 23 and adjustable mounting bolts 25. The movable framework 18' for the transversely movable units are supported by transversely spaced pairs of rolls at both the front and rear framework 10. Each set of rolls includes a lower roll 26 engaged with the lower surface of track 24, an upper roll 27 engaged with one of the upper surfaces of track 24 and a side roll 28 engaged with a vertical inwardly facing surface on track 24 (FIGURE 11). The framework member 18' is therefore mounted on track 24 for transverse movement along the length thereof, but all other movement of framework member 18 relative to framework 10 is eliminated by the multi-directional rolling contact of rolls 26, 27 and 28.

The transverse joint cutting units also include an elevationally movable frame 22' which is supported by the framework member 18' in the same manner as previously described with relation to FIGURES 4-7. All of the previously described mechanisms are shown in the transverse units with the exception of the wobbly disc 64. The disc 64 is an accessory item which might or might not be used, depending upon the particular circumstances of the job. It is preferable when the joint is to be formed in concrete that has set for an appreciable time after pouring, since disc 64 has a greater cutting capacity than a stationary blade. However, on freshly poured concrete, a blade or other slotting device has been found to be satisfactory alone.

The one deviation in the structure shown in FIGURES 9 and 10, which must move across the joinder of the slope and bottom canal slab surfaces, is a shortening of the dimension between the two transversely spaced roll assemblies. The location of the roll assemblies in this unit should be approximately adjacent to the pivotal axis at formed at the rear of the joint cutting device 411 and the pivotal axis of the bracket 56 that connects the lower end of link to the front of the plate 44. In this manner the blade 42 will be enabled to cut a slot of substantially uniform depth across the radius of the connection between the horizontal and sloped pavement sections.

The transverse joint 8 across the canal cross section is formed while framework 10 is stationary. The four joint cutting units are each moved by a cable 78 extending along framework 10 and connected to each framework member 18 by a bracket 83 at the front end thereof. Suitable guide rollers 84 are provided on framework 10 for the cable 78. The cable 78 is powered by a drum and motor unit at the upper end of framework 10. A counterweight 81 is provided in a track 82 extending along framework 10 to balance the weight of the units which must be pulled by cable 78 up the angular slope of the canal wall.

The operation of this device is believed to be evident from the previous disclosure. The forming of a longitudinal joint occurs during longitudinal movement of framework 10 relative to the previously poured slab. When a transverse joint 8 is to be cut or otherwise formed, the framework 10 is stopped relative to the slab. The several joint cutting units, positioned at their lowermost locations relative to framework 10, are then drawn upwardly by operation of cable 78. Prior to such movement, the joint cutting device 41 on each unit would be lowered into contact with the concrete by release of the solenoid 75 in each control unit. The release of each controlling solenoid 75 permits the individual elements 73 to monitor the proper pre-selected elevation of frame 22 relative to the concrete surface and thereby insures uniform depth in the joint.

When the units have moved upwardly a distance such that one overlaps the joint cut by the unit forward of it, they are again raised by operation of solenoids 75'and returned to their lower position by the cables 78. This return motion can be effected during successive longitudinal movement of the framework .10. During such longitudinal movement, the longitudinal joint 9 is automatically cut by the joint cutting device 41 on frame 22, also automatically controlled as to depth by the associated spool valve 73. The track cutting device 41 can be raised from contact with the slab by operation of solenoid 75 when a longitudinal joint is not desired or when the framework 10 is traveling along the slab from one job location to another.

Many variations could be made in the joint forming device itself without deviating from the scope of this invention. The slotting device shown utilizes a vertical blade that penetrates the concrete surface with a reciprocating vertical movement imparted to the blade along its forward end. This has been found to be effective in insuring the proper penetration of the blade through the concrete when the concrete is freshly poured. In some instance the addition of disc 64 forward of the blade 42 (FIGURE 6) is advisable to better insure the proper depth penetration of the cutting elements. The use of the rear cutting device 58 provides additional length in the joint forming arrangement and permits even surface formation along the walls of the joint. It is to be understood that a joint material, whether pre-formed or liquid, can be inserted into the concrete through the blade 42, which can be hollow, tubular or open.

Since modifications can be made in the structure without deviating from the basic mounting arrangement and control elements described, only the following claims are intended to specify the scope of my invention.

Having thus described my invention, I claim:

1. A joint forming apparatus for a concrete slab, having an upwardly facing slab surface, comprising:

a rigid ground supported framework movably mounted relative to the slab and positioned across said slab at a location upwardly adjacent to the slab surface;

a frame movably mounted on said framework for elevational adjustment relative thereto;

power operated means operatively connected between said frame and said framework for elevationally positioning said frame relative to said framework;

joint forming means carried by said frame and protruding downwardly therefrom, said joint forming means comprising a slotting device having an arcuate lower edge;

and control means on said frame operatively connected to said power operated means, said control means comprising an element movably supported on said frame for contacting the slab surface at a position adjacent to said joint forming means and means operatively connected to said element and to said power operated means for maintaining said frame at a constant elevation relative to said slab surface, the arcuate lower edge of said slotting device being extended through the slab surface when said element is in contact with the slab surface.

2. A joint forming apparatus as set out in claim 1 wherein said control means further comprises:

means on said frame selectively engageable with the slab contacting element for lifting said element from contact with the slab surface.

3. A joint forming apparatus as set out in claim 1, further comprising:

mounting means on said framework operatively supporting said frame for movement of the frame relative to said framework in a direction transverse to the intended direction of movement of said framework relative to the slab.

4. An apparatus as defined in claim 1 wherein the rear end of said slotting device is pivotally carried on said frame about a transverse horizontal axis,

and power means on said frame operatively connected to the forward end of said slotting device to impart a reciprocating vertical movement thereto.

5. An apparatus as defined in claim 1 further comprising:

a cutting disc rotatably mounted on said framework forward of said slotting device with the lower tangential edge of said disc being at an elevation substantially identical to the lowermost elevation of said slotting device;

means on said frame rotatably carrying said disc and imparting thereto an'eccentric wobbling movement about a transverse horizontal axis;

and power means on said frame operatively connected to said disc to rotate said disc about said transverse aXlS.

References Cited UNITED STATES PATENTS Earley et a1.

Guntert et al 94-51 XR Ackerman et al 94-46 Hanson 9446 v JACOB L. NACKENOFF, Primary Examiner. 

